Whatever takes form is false. Only the formless consciousness pervades the whole universe, which is in the form of “mind” endures. When one understands this truth of the true existence, the birth, life, death and the world are mere mirage. For conciousness is infinite, within the three states and without the tree states. As water is everywhere in the cloud and snow, so consciousness is everywhere, pervades in everything and everywhere in all the three states.
Knowing this universe is like foam, realizing its nature --a mirage-- cutting it out through the sword of wisdom, the mind becomes one with the nondual essence, which is consciousness.
The whole universe, which is in the form of mind, is indeed consciousness. The consciousness is ultimate truth. If one realizes consciousness as self the duality ceases to be reality. The nature of the consciousness is formless and nondual. The self-knowledge is the only tool to overcome the ignorance, which is the cause of duality.
The ultimate Truth is that which is eternal. That which is the truth has to be eternal and the eternal thing is nothing but the truth alone. In this sense, consciousness alone is truth because that is the only which is aware of the coming and going of the mind, which is in the form of universe. The universe which appears as waking or dream is mere mirage created out of consciousness.
The universe is mere illusionary appearances on this consciousness. These appear due ignorance. The ultimate truth is only one and that is consciousness. To assimilate this, one has to analyse the three states.
If one looks at the universe on the standpoint of the ego (ignorance) then the world appears to be real. This is called "Apparently real" as the knowledge of this universe (mind (I)) vanishes on the rise of knowledge of its substratum i.e., consciousness. Though universe was cognized in the consciousness to be truly existent, a closer inspection revealed its nature to be illusory. Thus it is only "apparently real". Here the universe (mind) is merely superimposed on the consciousness though in truth, it never existed there.
The whole universe with its diverse names and forms is a mere superimposition on consciousness; as the knowledge of the substratum (consciousness) arises, the illusory appearance of universe is destroyed.
Once the knowledge of the consciousness arises, this entire universe, which is I the form of mind, is realized to be a mere illusion. Hence the universe [mind] which will continue to exist as reality, till the rise of the knowledge of the consciousness.
The consciousness is the absolute reality as it never gets altered in any divisions of time – past, present or future. This neither has a beginning nor an end. This is beyond names and forms. It cannot be described as "This is ultimate truth".
Ultimate is that which remains after negating the falsehood. Hence, in truth, the body, ego universe are the same as the consciousness and all the objects within the universe [mind] are nothing but consciousness.
Illusion is the cause for the notion of diversity. The nature of the illusion cannot be ascertained. It is a mysterious energy whose nature cannot be determined to be either truth or untruth. It is the cause for this ignorance. And ignorance is cause of experiencing the duality as reality.
Illusion appears to be real only till the knowledge of the consciousness arises. Once this self-knowledge arises, illusory reality becomes unreal. The entire universe along with its cause disappears at the rise of the self- knowledge. Because the self, which is consciousness becomes fully aware of its formless nondual true nature and finds itself in everything and everywhere in the illusion.
Thus consciousness alone is real. The entire universe, which is in the form of mind is mere mirage created out of consciousness. The mirage is non-different from the consciousness. Realizing the consciousness as true self is freedom.